Past Research at Rockefeller Wildlife Refuge
Alligator
The American alligator (Alligator mississippiensis) was affected by unregulated harvest in the early 1900s. However, during the 1960s and 1970s extensive research and monitoring by RWR research staff (led by Ted Joanen and Larry McNease), as well as a period of time when no harvest was allowed, led to population recovery of American Alligators. Alligator numbers recovered to the point where limited, carefully regulated harvests were again allowed. There are now some 1.5 million alligators in Louisiana, and some 30,000 – 40,000 wild alligators harvested statewide each year. A limited nuisance harvest is conducted on RWR to avoid human-alligator conflicts in areas of high public use, primarily near water control structures.
The research conducted at RWR on alligator egg incubation, culture of juveniles, nutrition, and captive propagation led to the development of a farming/ranching program statewide, which has become a multi-million dollar industry within the state. The wild and farm programs have been valued at over $60 million in peak years. These programs and the utilization philosophy are recognized internationally as models for sustained use management and have been applied to crocodilian species worldwide.
The American alligator (Alligator mississippiensis) was affected by unregulated harvest in the early 1900s. However, during the 1960s and 1970s extensive research and monitoring by RWR research staff (led by Ted Joanen and Larry McNease), as well as a period of time when no harvest was allowed, led to population recovery of American Alligators. Alligator numbers recovered to the point where limited, carefully regulated harvests were again allowed. There are now some 1.5 million alligators in Louisiana, and some 30,000 – 40,000 wild alligators harvested statewide each year. A limited nuisance harvest is conducted on RWR to avoid human-alligator conflicts in areas of high public use, primarily near water control structures.
The research conducted at RWR on alligator egg incubation, culture of juveniles, nutrition, and captive propagation led to the development of a farming/ranching program statewide, which has become a multi-million dollar industry within the state. The wild and farm programs have been valued at over $60 million in peak years. These programs and the utilization philosophy are recognized internationally as models for sustained use management and have been applied to crocodilian species worldwide.
Bald Eagles
Only 4 active Bald Eagle (Haliaeetus leucocephalus) nests were found in Louisiana between 1954 and 1960. In 1972, only six nests were reported and declines were attributed to the link between pesticides and
eggshell thinning. Other secondary factors also contributed to its decline, including habitat destruction, disturbance of nests, and poaching. Formal
Bald Eagle surveys by RWR staff began in 1984 (led by former RWR biologist Tom Hess) to determine the distribution/abundance of Bald Eagle populations. By 2008, the Bald Eagle had been taken off the federal endangered species list,
partially due to recovered Louisiana populations that maintain ~400-500
active nests throughout the state. From 2011-2014, RWR collaborated with Nick Smith and Dr. Al Afton of the Louisiana Cooperative Fish and Wildlife Research Unit at LSU to track Bald Eagles wintering in Louisiana. Birds were captured with rocket nets and equipped with satellite transmitters. Many of the satellite tagged Bald Eagles were faithful to migratory corridors and summered in Canada.
Only 4 active Bald Eagle (Haliaeetus leucocephalus) nests were found in Louisiana between 1954 and 1960. In 1972, only six nests were reported and declines were attributed to the link between pesticides and
eggshell thinning. Other secondary factors also contributed to its decline, including habitat destruction, disturbance of nests, and poaching. Formal
Bald Eagle surveys by RWR staff began in 1984 (led by former RWR biologist Tom Hess) to determine the distribution/abundance of Bald Eagle populations. By 2008, the Bald Eagle had been taken off the federal endangered species list,
partially due to recovered Louisiana populations that maintain ~400-500
active nests throughout the state. From 2011-2014, RWR collaborated with Nick Smith and Dr. Al Afton of the Louisiana Cooperative Fish and Wildlife Research Unit at LSU to track Bald Eagles wintering in Louisiana. Birds were captured with rocket nets and equipped with satellite transmitters. Many of the satellite tagged Bald Eagles were faithful to migratory corridors and summered in Canada.
Brown Pelican Restoration in Louisiana
The eastern Brown Pelican (Pelecanus occidentalis) is the Louisiana state bird, but it had virtually disappeared from the state by 1963, with environmental pesticide contamination as a plausible link to declines. In 1968, staff biologists at RWR (led by Larry McNease, Ted Joanen, and David Richard) initiated a program to reintroduce Brown Pelicans back into their historical range of coastal Louisiana. Since the inception of the program, RWR personnel have monitored the incredibly successful reintroduction via aerial surveys. Between 1971 and 2010, over 350,000 Brown Pelicans young were produced in Louisiana, with 14 active colonies in 2008 producing ~24,620 fledglings. Another important milestone during the program was the natural expansion of Brown Pelicans to Rabbit Island in southwestern Louisiana (Cameron Parish) in 2003. This colony has grown rapidly in 12 years to approximately 1700-2200 nests produced in 2014.
The eastern Brown Pelican (Pelecanus occidentalis) is the Louisiana state bird, but it had virtually disappeared from the state by 1963, with environmental pesticide contamination as a plausible link to declines. In 1968, staff biologists at RWR (led by Larry McNease, Ted Joanen, and David Richard) initiated a program to reintroduce Brown Pelicans back into their historical range of coastal Louisiana. Since the inception of the program, RWR personnel have monitored the incredibly successful reintroduction via aerial surveys. Between 1971 and 2010, over 350,000 Brown Pelicans young were produced in Louisiana, with 14 active colonies in 2008 producing ~24,620 fledglings. Another important milestone during the program was the natural expansion of Brown Pelicans to Rabbit Island in southwestern Louisiana (Cameron Parish) in 2003. This colony has grown rapidly in 12 years to approximately 1700-2200 nests produced in 2014.
Fisheries Ecology and Aquaculture
Fisheries research has been a significant part of the Rockefeller research program since 1965. Biologists led by Guthrie Perry worked closely in the design and implementation of management strategies with positive benefits
to marine organisms. Early projects in the 1960s focused on life history studies on catfish, shrimp, and other marine organisms. Later, several species were screened for aquaculture potential in an effort to encourage private landowners to continue managing their property as coastal wetlands.
In 1972, RWR staff initiated a program to reintroduce striped bass (Morone saxatils) into waterways of southwestern Louisiana. Following the striped bass project, the fish rearing ponds have been stocked with Florida-strain largemouth bass (Micropterus salmoides) from 2000 to present. Advanced fingerlings from Rockefeller have been stocked onto RWR and other waterbodies throughout the state in order to assist the Inland Fisheries division with their target objectives.
In addition to understanding the impacts of management units on waterfowl, it has been equally important to understand the impact of management regimes on marine organisms, with several cooperative studies with Louisiana State University and University of Louisiana - Lafayette initiated in the late 1980s.
Fisheries research has been a significant part of the Rockefeller research program since 1965. Biologists led by Guthrie Perry worked closely in the design and implementation of management strategies with positive benefits
to marine organisms. Early projects in the 1960s focused on life history studies on catfish, shrimp, and other marine organisms. Later, several species were screened for aquaculture potential in an effort to encourage private landowners to continue managing their property as coastal wetlands.
In 1972, RWR staff initiated a program to reintroduce striped bass (Morone saxatils) into waterways of southwestern Louisiana. Following the striped bass project, the fish rearing ponds have been stocked with Florida-strain largemouth bass (Micropterus salmoides) from 2000 to present. Advanced fingerlings from Rockefeller have been stocked onto RWR and other waterbodies throughout the state in order to assist the Inland Fisheries division with their target objectives.
In addition to understanding the impacts of management units on waterfowl, it has been equally important to understand the impact of management regimes on marine organisms, with several cooperative studies with Louisiana State University and University of Louisiana - Lafayette initiated in the late 1980s.
Marsh Ecology
Two methods allow RWR staff to assess and inventory marsh status: 1) water level and salinity surveys and 2) vegetative surveys. RWR staff monitor water levels and salinities across the refuge on a weekly and monthly basis. RWR staff also historically and currently monitor vegetative composition of refuge marshes to determine the impacts of management strategies on vegetative communities. Historical data on marsh types and vegetation data are found in O’Neil (1949), with future vegetative monitoring planned with contemporary methods (i.e., digital imaging and radar) in collaboration with U.S. Geological Survey. The refuge also has implemented integrated staff gauges to allow a more accurate and consistent measurement of water levels across the refuge.
Two methods allow RWR staff to assess and inventory marsh status: 1) water level and salinity surveys and 2) vegetative surveys. RWR staff monitor water levels and salinities across the refuge on a weekly and monthly basis. RWR staff also historically and currently monitor vegetative composition of refuge marshes to determine the impacts of management strategies on vegetative communities. Historical data on marsh types and vegetation data are found in O’Neil (1949), with future vegetative monitoring planned with contemporary methods (i.e., digital imaging and radar) in collaboration with U.S. Geological Survey. The refuge also has implemented integrated staff gauges to allow a more accurate and consistent measurement of water levels across the refuge.
Waterfowl
Mottled Duck (Anas fulvigula) population dynamics has been a major waterfowl focus area for RWR personnel. Since banding efforts began in 1994, ~40,000 mottled ducks have been banded in Louisiana. During the summer (June-August) Mottled Ducks are banded across coastal Louisiana, with RWR staff focusing efforts primarily in southwestern Louisiana. These banding efforts are critical to determine annual harvest rates and survivorship for Mottled Ducks, as well as to assist in the management of the species. The timing of banding efforts coincides with brood rearing and molt when ducks are easily captured by hand from an airboat at night. In 2007-2009, RWR collaborated on telemetry projects with LSU and Texas A & M on Mottled Ducks to determine habitat use and movements, particularly during brood rearing and molt. RWR staff also participate in winter waterfowl surveys of the coastal refuges/wildlife management areas, as well as spring aerial surveys for breeding Mottled Ducks.
Mottled Duck (Anas fulvigula) population dynamics has been a major waterfowl focus area for RWR personnel. Since banding efforts began in 1994, ~40,000 mottled ducks have been banded in Louisiana. During the summer (June-August) Mottled Ducks are banded across coastal Louisiana, with RWR staff focusing efforts primarily in southwestern Louisiana. These banding efforts are critical to determine annual harvest rates and survivorship for Mottled Ducks, as well as to assist in the management of the species. The timing of banding efforts coincides with brood rearing and molt when ducks are easily captured by hand from an airboat at night. In 2007-2009, RWR collaborated on telemetry projects with LSU and Texas A & M on Mottled Ducks to determine habitat use and movements, particularly during brood rearing and molt. RWR staff also participate in winter waterfowl surveys of the coastal refuges/wildlife management areas, as well as spring aerial surveys for breeding Mottled Ducks.